Field of the Invention
The present invention relates to an imprint apparatus and an article manufacturing method.
Description of the Related Art
The demand for micronization of semiconductor devices and MEMS and the like is increasing, and in addition to conventional photolithography technologies, a microfabrication technology in which an uncured resin on a substrate is molded by using a mold and a resin pattern is formed on a substrate is gaining attention. This technology is referred to as “imprint technology”, and it can form a fine structure on the order of several nanometers on a substrate. One example of an imprint technology is a photo-curing method. In an imprint apparatus that uses this photo-curing method, first an ultraviolet light-cured resin (imprint material, photo-cured resin) is applied to a shot, which is an imprint area on a substrate (wafer). Next, this resin (photo-cured resin) is molded by using a mold. In addition, a pattern of the resin is formed on the substrate by separating the cured resin after the resin has been cured by irradiating an ultraviolet light.
In this type of imprint apparatus, when a resin is filled into a fine contoured portion formed in a mold during the pressing of the mold and the resin on the substrate, there are cases in which a resin pattern does not form correctly because of unfilled portions occurring due to bubbles remaining in the resin. Thus, conventionally, an imprint apparatus has been proposed that suppresses the retention of bubbles by filling a gap space sandwiched between the mold and the substrate (resin) during pressing with a special gas. Japanese Translation of PCT International Application Publication No. JP-T-2007-509769 discloses an imprint lithography method that includes a step in which a gas having a high solubility or high diffusibility is fed at a position in close proximity to the viscous liquid resin on the substrate.
However, as disclosed in Japanese Translation of PCT International Application Publication No. JP-T-2007-509769, in a state in which only the gap space between a mold and a substrate is locally filled with a special gas, ambient air will flow from outside the gap space into the gap space when the substrate is moved (scanned) in a direction parallel to the mold. In this situation, because the effect is obtained in which the retention of bubbles is restrained by supplying a gas into the gap space, the gas concentration inside the gap space must, to a certain extent, be maintained at a high value. However, in this case, raising the gas concentration up to a high value is difficult due to the inflow of air. Therefore, in a conventional imprint apparatus, for example, the supplied amount of gas is large, and not just the inside of the gap space, but a wide area in the vicinity of the mold must be filled in advance.